Tag Archives: black holes

Monster black holes lurking in the centres of galaxies are hungrier than previously thought, Melbourne scientists have discovered.

Artist’s impression of a star being pulled into a black hole. Credit: Gabriel Perez Diaz

Astrophysicist Alister Graham and his team at Swinburne University have revealed that these so-called supermassive black holes consume a greater portion of their galaxy’s mass the bigger the galaxy gets. The discovery overturns the longstanding belief that these supermassive black holes are always a constant 0.2 per cent of the mass of all the other stars in their galaxy.

The world’s largest telescope, the Square Kilometre Array (SKA), is expected to generate more data in a single day than the world does in a year at present. And even its prototype, CSIRO’s ASKAP, is expected to accumulate more information within six hours of being switched on than all previous radio telescopes combined.

Such gargantuan streams of data require serious management, and that will be one of the jobs of the $80 million iVEC Pawsey Centre in Perth, which is due to be completed in 2013.

Einstein’s general theory of relativity predicts them, and they could be scattered throughout the Universe. But so far, gravitational waves— ‘ripples’ in the fabric of space and time—have never been detected. Several Australian teams of astronomers are trying to catch the first signs of one.

At the centre of a nearby galaxy lurks an object of huge interest, a super-massive black hole. CSIRO scientists have used their radio telescopes to take a picture of the galaxy surrounding it, a task some thought could not be done, because of the sheer size and radio brightness of the scene. The image of Centaurus A took about 1,200 hours of observations and a further 10,000 hours of computer processing to put together, but the work is already beginning to bear fruit.

“We didn’t generate this image just to make a pretty picture,” says lead scientist Ilana Feain of CSIRO Astronomy and Space Science. “We want to understand in detail how the energy from super-massive black holes influences the formation and evolution of their host galaxies.” Continue reading Recording the impact of a super-massive black hole→

THE ZADKO TELESCOPE MAKING OBSERVATIONS NEAR GINGIN, 70 KILOMETRES NORTH OF PERTH. CREDIT: JOHN GOLDSMITH/CELESTIAL VISIONS.

You have to be well prepared, quick and lucky to take a picture of an explosion, especially if that explosion occurred 11 billion years ago in a remote part of the Universe. Having the right equipment, plus friends in high places, certainly helps. And that’s exactly what the Zadko Telescope—managed by the University of Western Australia at the Gingin Observatory about 70 kilometres north of Perth—does have.

In December 2008, just after it was installed, the telescope was first on the scene to record for future analysis the afterglow of a momentous event—a huge explosion as a star collapsed into a black hole releasing a massive gamma-ray burst. It’s the kind of happening the one-metre Zadko Telescope, currently the largest optical telescope in Western Australia, was built to observe. And it performed flawlessly, outpacing the world’s most powerful telescopes at the European Southern Observatory in Chile.

Australian astronomers have long been contributing to our understanding of a strange cosmological phenomenon—the Universe’s missing matter.

In the early 1970s, Ken Freeman of the Australian National University (ANU) determined that spiral galaxies must contain more matter than we can see. He postulated that dark matter—an invisible material first proposed 40 years earlier—must make up at least half the mass of these galaxies. Now, patches of dark matter are thought to be scattered across the Universe, playing a major role in holding galaxies and groups of galaxies together. Continue reading Spinning galaxies reveal missing matter→

Imagine printing your own room lighting, lasers, or solar cells from inks you buy at the local newsagent. Jacek Jasieniak and colleagues at CSIRO, the University of Melbourne and the University of Padua in Italy, have developed liquid inks based on quantum dots that can be used to print such devices and in the first demonstration of their technology have produced tiny lasers. Quantum dots are made of semiconductor material grown as nanometre-sized crystals, around a millionth of a millimetre in diameter. The laser colour they produce can be selectively tuned by varying their size.

High tech cling wraps that ‘sieve out’ carbon dioxide from waste gases can help save the world, says Melbourne University chemical engineer, Colin Scholes who developed the technology. The membranes can be fitted to existing chimneys where they capture CO2 for removal and storage. Not only are the new membranes efficient, they are also relatively cheap to produce. They are already being tested on brown coal power stations in Victoria’s La Trobe Valley, Colin says. “We are hoping these membranes will cut emissions from power stations by up to 90 per cent.”

John O’Sullivan’s search for exploding black holes led to fast, reliable Wi-Fi. Credit: Department of Innovation, Industry, Science and Research

When you use a Wi-Fi network—at home, in the office or at the airport—you are using patented technology born of Australian astronomy.

Australia’s CSIRO created a technology that made the wireless LAN fast and robust. And their solution grew out of 50 years of radio astronomy and one man’s efforts to hear the faint radio whispers of exploding black holes.